A device which is described in PTL 1 is known as a type of the electronic component mounting machine. As illustrated in FIG. 1 of PTL 1, in order to convey each of first and second substrates 2-1 and 2-2 along a conveyance direction and mount electronic components thereon, the electronic component mounting machine is provided with first and second substrate conveyance lanes 3 and 13 which cause the first and second substrates 2-1 and 2-2 to stop at respective predetermined substrate stopping positions, and first and second mounting heads 4 and 14 which respectively mount the electronic components of first and second component supplying devices 8A and 18A (8B and 18B) to the first and second substrates 2-1 and 2-2 which are stopped in the respective predetermined substrate stopping positions.